Unleash the secrets of Cartagena in an unforgettable walking tour through the legendary Castillo San Felipe de Barajas — a UNESCO World Heritage Site and the most formidable military fortress ever built by the Spanish in the Americas. Built over two centuries on the strategic hill of San Lázaro, the castle was designed with one purpose: to be impossible to defeat. Step inside its network of tunnels and hidden passageways — an underground labyrinth engineered to move soldiers invisibly and defend the city against any invader who dared approach. Your guide will bring to life the castle's most defining moment — the Battle of 1741, when the one-eyed, one-armed admiral Blas de Lezo repelled a British fleet of 186 ships in one of history's greatest military upsets — along with the stories of French corsairs and English pirates who made Cartagena the most attacked port in the Americas. Climb to the highest points for breathtaking panoramic views of the Caribbean Sea and Cartagena.